* Algeria become first African team to score four in World Cup game
* The North Africans now in pole position to earn last 16 spot
* South Korea coach said his team's defence was "not up to standard" (Adds detail, quotes)
By Steve Keating
PORTO ALEGRE, Brazil, June 22 (Reuters) - Algeria opened the goal scoring floodgates swamping South Korea 4-2 in a thrilling World Cup Group H clash on Sunday that kept hopes of securing a spot in the last 16 alive and triggered celebrations across the Arab nation.
Algeria's first World Cup victory since 1982 moved them into second place in the group on three points behind Belgium, who beat Russia 1-0 earlier in the day to top the standings on six.
South Korea and Russia, who drew 1-1 in their tournament opener, both have one point.
The only Arab presence in the tournament, the 'Desert Foxes' have never made it past the first round but are now in pole position to earn a spot in the knockout phase.
Belgium have already booked one of the group's two slots in the last 16.
After seeing a 28-year World Cup goal drought end in a 2-1 loss to Belgium in their opener, the Algerians unleashed a goal scoring spree on the Koreans, Islam Slimani, Rafik Halliche and Abdelmoumene Djabou all finding the net in an astonishing first half display of all-out attacking football.
"We played an almost perfect first period," Algeria coach Vahid Halilhodzic said. "The second period was not as good - they may have been more relaxed."
Halilhodzic opted for wholesale changes to the starting lineup that faced Belgium bringing in five new faces, including forwards Slimani and Djabou.
"I took into account how Korea played, I wanted some fresh players, players who wanted revenge (for Algeria's opening game defeat), who could worry the Korean team and make it difficult for them," Halilhodzic said.
The Algerians seized the early initiative dominating possession and finally saw their ambition rewarded in the 26th minute when Slimani ran onto a perfectly placed through ball from Carl Medjani. After muscling his way past two Korean defenders, Slimani stabbed the ball over a charging Jung Sung-ryong bringing the crowd to their feet.
Just two minutes later the Algerian supporters were on their feet at Beira Rio stadium celebrating again, Halliche adding a second with a powerful header off a Djabou corner kick.
The reeling Koreans were shocked again in the 38th minute when an unmarked Djabou took advantage of some appalling defending and coolly slotted home a third on brilliant feed from Slimani.
South Korea, however, were not about to throw in the towel and started the second half with an urgency missing at the start, Son Heung-min turning smartly in the box to fire between Rais Mbolhi's legs in the 50th minute.
The Asians continued to press forward and Ki Sung-yeung forced a sensational diving save from Mbolhi with a thundering long range shot.
On the back foot, Algeria took the steam out of the Korean rally when Yacine Brahimi netted on the counter-attack making them the first African team to score four goals in a World Cup match.
The end-to-end action continued, the never-say-die Koreans pulling another one back in 72nd minute when Koo Ja-cheol scored from a scramble in front of the Algerian net to make it 4-2.
"The defence wasn't what it should have been, our players were not up to standard," South Korea's coach Hong Myung-bo said.
"There was not enough communication between the defensive players. It was something we can learn from but the three goals in the first half were really regrettable." (Additional reporting by Peter Rutherford, Editing by Nigel Hunt)